When the market is not cleaning up vacant buildings, which cause negative effects on the economy, procurement can be an objective and efficient tool to let the government clean up instead. The government would first decide the amount and typology of buildings to be removed. Then private parties can propose projects to demolish these, at a certain price. The projects with the lowest cost per unit of building win in this contest and get executed.
A proxy for the amount to spend by the government is the potential rise of the value of the total building stock, which is largely an empirical question. Funding could then also realistically come from higher real estate taxes, as the government intervention creates maximum value.